Sunday, February 18, 2007

Entropy Decreasing?

A few days ago, I had a big scare. The scare came from the home of the Loch-ness Monster, Scotland. The scare almost destroyed me.

My career looked like it was going to go drown the drain. The middle east looked like it would not be in so much trouble anymore; and Exxon Mobil stocks would be on the verge of plummeting. And global warming looked like it was about to stop happening.

You see, I work on Energy Technologies. My guide makes his $$$$ by helping incrementally increase the efficiency of gas turbine engines by the order of 0.0000001%. My entire career depends on two things:

  • Energy Scarcity
  • Bitchiness of Navier-Stokes. (this will be discussed later).
So, when I read that some people invented a genuine microscopic Maxwell Daemon, I was shell-shocked. (The U.S government invented the macroscopic Maxwell Daemon. I have scrutinized it here a long ago). Doing some horribly complicated nano-molecular chemistry (in the description of which the term "rotaxane" is employed), a molecular ratchet has been developed by Serelli . in Edinburgh, Scotland. Undoubtedly, they developed it to keep the Loch Ness monster company.

A real Maxwell Daemon will destroy energy scarcity. Here's how.

  • Suppose you have a room filled with slow molecules colliding with each other. They form the "cold fluid".
  • Suppose you then introduce some really fast molecules to the room. This would be the "hot fluid".
  • These fast molecules will collide with the slower ones - and they will keep colliding forever- eventually each and every molecule has the same velocity on average. The system attains a state of equilibrium. The molecules still keep colliding, mind you. But they do not transfer any energy on the net to each other. The gas it as the "equilibrium" temperature.
  • Though the odd molecule might get as fast as the one of the original "hot fluid" molecules, it will be a statistical anomaly. You won't be able to extract a set of "fast" molecules. The introduction of the "hot" gas is an irreversible process.
  • A Maxwell Daemon would do the needful, actually.
  • Suppose you introduced an "impenetrable" barrier dividing the room into two. Suppose, you then employed the aforementioned daemon to let only the faster molecules across. Presto! You have hot fluid on one side - and cold fluid on the other side. Build an engine and you can generate electricity.
  • The Edinburgh daemon does something like this.
  • A PMM2 could have been achieved. No more energy scarcity.

You can imagine how scared I was on reading the Nature article. Scared, I was, until I realized that the Daemon sought photons as renumeration. The Daemon is light powered. You need to expend energy in ensuring that the Daemon does what it is supposed to.

The second law comes across unscathed - at least for now.

1 comment:

Radha said...

This is really creepy - the fact that a friend was just mentioning something on the Brownian ratchets, and I come home from Walmart to find that you are blogging about too. My work on Brownian motion notwithstanding, why does it appear that everyone seem to be understanding it better than I do?!!!